Problem: Simplify the expression. $(-3z^{3}+z)(4z^{2}-3z)$
Solution: First use the distributive property. $ - 3 z^3 (4 z^2) - 3 z^3 (-3 z) + z (4 z^2) + z (-3 z) $ Simplify. $-12z^{5}+9z^{4}+4z^{3}-3z^{2}$